The humble padlock has been a mainstay of security for a long time. While outwardly simple, these 2,500 year old inventions have been used to secure everything from loads on trading routes to gates into our backyards. But they've now been given the "smart" treat - replacing the lock-and-key with a mechanism that is activated via a secure app on your smartphone. Don and Bone sell a variety of different Smartlock devices. I've tested their travel lock for suitcases and the Locksmart Mini - which is pretty darn big for something with the "mini" tag.